Shared Socioeconomic Pathways

Shared Socioeconomic Pathways
Name	Shared Socioeconomic Pathways
Abbreviation	SSPs
Type	Scenario framework
Developed by	Intergovernmental Panel on Climate Change; International Institute for Applied Systems Analysis; National Aeronautics and Space Administration
First published	2010s

Contents

Shared Socioeconomic Pathways

The Shared Socioeconomic Pathways are a suite of scenarios used to describe plausible futures for population, United Nations-related development, and technological change to inform Intergovernmental Panel on Climate Change assessments and modeling efforts by institutions such as the International Institute for Applied Systems Analysis, NASA, and the National Oceanic and Atmospheric Administration. The SSPs provide harmonized storylines that climate modelers at centers like the Hadley Centre, Max Planck Institute for Meteorology, and Lawrence Berkeley National Laboratory use alongside emissions trajectories developed by groups including the Integrated Assessment Modeling Consortium and the Potsdam Institute for Climate Impact Research.

Overview

The SSP framework links narratives that originated in workshops convened by the Intergovernmental Panel on Climate Change, the IIASA and collaborators such as the World Bank, Organisation for Economic Co-operation and Development, and the European Commission with quantitative projections produced by modeling teams at the International Energy Agency, Princeton University, Stanford University, and the University of Oxford. Each SSP storyline describes alternative pathways for demographic change influenced by institutions like the United Nations Population Division, technological diffusion exemplified in historical cases such as the Industrial Revolution and policies associated with treaties like the Paris Agreement, and socioeconomic trends reflected in reports from the World Health Organization and the International Monetary Fund.

Development of the SSPs combined narrative crafting by authors affiliated with organizations including the Stockholm Environment Institute, Carnegie Institution for Science, Resources for the Future, and the World Resources Institute with quantitative downscaling methods employed by teams at the National Center for Atmospheric Research, Columbia University, and the Massachusetts Institute of Technology. Methodological elements incorporate demographic inputs from the United Nations Population Division and economic projections informed by historical series from the Conference Board and the Organisation for Economic Co-operation and Development. Modeling workflows use integrated assessment models developed at the Fossil Fuel Studies Group, IIASA, Potsdam Institute, RFF, and university groups such as Yale University and Imperial College London to translate narratives into variables like urbanization, land use change, and energy demand.

The five canonical pathways were authored by multi-institution teams drawing on expertise from the World Bank, United Nations Environment Programme, European Environment Agency, and academic centers including University of California, Berkeley, ETH Zurich, Tokyo Institute of Technology, and Australian National University. SSP1 emphasizes sustainable development trajectories similar to policy agendas advanced at summits like the United Nations Conference on Sustainable Development and programs by the United Nations Development Programme and Bill & Melinda Gates Foundation. SSP2 represents a midpoint pathway akin to baseline projections in reports by the Intergovernmental Panel on Climate Change and the World Economic Forum. SSP3 describes regional rivalry and fragmentation reminiscent of periods such as the Interwar period and policies associated with protectionism promoted by organizations like the World Trade Organization-critics. SSP4 outlines high inequality scenarios reflecting analyses by the International Monetary Fund and Oxfam on wealth concentration. SSP5 posits fossil-fueled development comparable to historical expansions chronicled in works by authors at institutions like Harvard University and Princeton University.

Climate model centers such as the Met Office Hadley Centre, Max Planck Institute for Meteorology, Geophysical Fluid Dynamics Laboratory, and the European Centre for Medium-Range Weather Forecasts integrate SSP socioeconomic inputs with radiative forcing pathways from energy-system models produced by groups like the Integrated Assessment Modeling Consortium, the IIASA, and the Potsdam Institute for Climate Impact Research. Integrated assessment models including those developed at IIASA, FINE, MESSAGE, and university teams at Stanford University and Massachusetts Institute of Technology translate SSP narratives into emissions, land-use, and concentration trajectories used by earth system models such as CESM, MPI-ESM, and HadGEM for runs in the Coupled Model Intercomparison Project exercises.

Policymakers at bodies like the United Nations Framework Convention on Climate Change, negotiators to the Conference of the Parties, and advisory panels to the European Commission and national agencies such as the United States Environmental Protection Agency use SSP-based outputs to assess mitigation options evaluated by analysts at McKinsey & Company, IIASA, and academic groups at Columbia University and Imperial College London. SSP scenarios inform vulnerability assessments by organizations including the World Bank, adaptation planning undertaken by the Green Climate Fund, and economic assessments cited in reports from the Intergovernmental Panel on Climate Change and the Organisation for Economic Co-operation and Development.

Critiques have been raised by scholars from institutions such as Oxford University, University of Cambridge, London School of Economics, and advocacy groups like Friends of the Earth regarding representation of equity and historical responsibility, echoing methodological debates in literature from the Journal of Climate, Nature Climate Change, and commentaries by analysts at the International Institute for Environment and Development. Other limitations noted by analysts at the World Resources Institute, Potsdam Institute, and independent researchers include challenges in downscaling to national contexts like India, China, Brazil, and United States and gaps identified relative to sector-specific models used by agencies such as the International Energy Agency and the Food and Agriculture Organization.

Category:Climate change scenarios